A glass bottom boat is a boat with sections of glass, or other suitable transparent material, below the waterline allowing passengers to observe the underwater environment from within the boat. The view through the glass bottom is better than simply looking into the water from above, because one does not have to look through optically

Optics

Optics is the branch of physics which involves the behavior and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behavior of visible, ultraviolet, and infrared light...

 erratic surface disturbances. The effect is similar to that achieved by a diving mask

Diving mask

A diving mask is an item of diving equipment that allows scuba divers, free-divers, and snorkelers to see clearly underwater. When the human eye is in direct contact with water as opposed to air, its normal environment, light entering the eye is refracted by a different angle and the eye is unable...

, while the passengers are able to stay dry, out of the water.

Use

Glass bottom boats are used almost exclusively for giving tours, as they are usually designed to allow the maximum number of tourists to view out the glass bottom

Glass floor

This article is about a structural feature. For the expression concerning limitations on advancement, see glass ceiling. For the 2004 Maritime album, see Glass Floor....

 and are not really suitable for other uses.
Glass bottom boats are in use in nearly every seaside tourist destination. However many of them are gradually being replaced by semi submarine

Semi submarine

Semi-submarines are submersibles vessels that are capable of diving, similarly to submarines. However, unlike submarines, they cannot be entirely submerged below the surface of the water.- Design :...

s. That type of vessels offer a better view of the marine life.

History

Glass bottom boats were first used near Santa Catalina Island

Santa Catalina Island, California

Santa Catalina Island, often called Catalina Island, or just Catalina, is a rocky island off the coast of the U.S. state of California. The island is long and across at its greatest width. The island is located about south-southwest of Los Angeles, California. The highest point on the island is...

 off the coast of Southern California

Southern California

Southern California is a megaregion, or megapolitan area, in the southern area of the U.S. state of California. Large urban areas include Greater Los Angeles and Greater San Diego. The urban area stretches along the coast from Ventura through the Southland and Inland Empire to San Diego...

. They also became popular in Florida at several areas of natural springs that became tourist attractions, for example, Silver Springs

Silver Springs Nature Theme Park

Silver Springs Nature Theme Park is a zoological park located in Silver Springs, Florida, USA, east of Ocala. Although not truly a theme park, Silver Springs is a nature and zoological park occupying land owned by the state of Florida as part of the Silver River State Park.The property for the park...

, Wakulla Springs, Rainbow Springs, and Weeki Wachee Springs

Weeki Wachee Springs

Weeki Wachee Springs is a natural tourist attraction located in Weeki Wachee, Florida, where underwater performances by "mermaids", women dressed with fins about their legs as well as other fancy outfits, can be viewed in an aquarium-like setting in the spring of the Weeki Wachee River...

.

Typical tours in these boats include views of underwater flora and fauna, reef

Reef

In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....

s, shipwrecks, and other underwater sights.